Various electro-optical systems have been developed for reading optical indicia, such as bar codes. A bar code is a coded pattern of graphical indicia comprised of a series of bars and spaces of varying widths, the bars and spaces having differing light reflecting characteristics. Some of the more popular bar code symbologies include: Uniform Product Code (UPC), typically used in retail stores sales; Code 39, primarily used in inventory tracking; and Postnet, which is used for encoding zip codes for U.S. mail. Systems that read and decode bar codes employing 1-dimensional imagers, charged coupled device (CCD), or complementary metal oxide semiconductor (CMOS) based imaging systems are typically referred to hereinafter as imaging systems, imaging-based bar code readers or bar code scanners.
Imaging-based bar code reader systems electro-optically transform the graphic indicia into electrical signals, which are decoded into alphanumerical characters that are intended to be descriptive of the article or some characteristic thereof. The characters are then typically represented in digital form and utilized as an input to a data processing system for various end-user applications such as point-of-sale processing, inventory control and the like.
Imaging-based barcode reader systems that include CCD, CMOS, or other imaging configurations comprise a plurality of photosensitive elements (photosensors) or pixels typically aligned in an array pattern that could include a number of arrays. The imaging-based bar code reader systems employ light emitting diodes (LEDs) or other light sources for illuminating a target object, e.g., a target bar code. Light reflected from the target bar code is focused through a lens of the imaging system onto the pixel array. As a result, the focusing lens generates an image from its field of view (FOV) that is projected onto the pixel array. Periodically, the pixels of the array are sequentially read out creating an analog signal representative of a captured image frame. The analog signal is amplified by a gain factor, by for example an operational amplifier. The amplified analog signal is digitized by an analog-to-digital converter. Decoding circuitry of the imaging system processes the digitized signals representative of the captured image frame and attempts to decode the imaged bar code. The decoding circuitry can be in the form of an application specific analog circuit (ASIC) or internal circuitry relating to a microprocessor.
Imaging scan engines for barcode reading and scanning have been available to OEMs for a number of years. The scan engines typically include a senor array and are a convenient for adding barcode reading capability to any product in need of such technology.
In existing linear imaging scan engines, the circuit board is typically positioned parallel to the axis of the optical system. Such configuration requires the presence of either a fold mirror in between the image sensor found in the scan engine and its focusing lens. Alternatively, the image sensor is remotely mounted from a main circuit board, requiring a flex circuit or a secondary circuit board for making a connection between the image sensor and main circuit board. Such constructions are expensive to manufacture and undesirably command a large amount of space.